Answer: a. I, II, III, IV
Explanation:
The Boston strike of 1919 saw the Boston Police go on strike after their Police Commissioner Edwin Curtis, refused to deal with any form of union activity in the Boston police force.
As a result of the strike, there was violence in the city and Calvin Coolidge who was governor at the time, called in the National Guard. When order was restored, Edwin Curtis fired the AFL representatives and other striking officers and replaced them with new and better paid ones.
